package org.eclipse.aether.util.graph.transformer;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   * 
   *  http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.util.IdentityHashMap;
  import java.util.Map;
  import static java.util.Objects.requireNonNull;
  
  import org.eclipse.aether.RepositoryException;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.collection.DependencyGraphTransformationContext;
  import org.eclipse.aether.collection.DependencyGraphTransformer;
  import org.eclipse.aether.graph.Dependency;
  import org.eclipse.aether.graph.DependencyNode;
  
  /**
   * Set "groupId:artId:classifier:extension" as conflict marker for every node.
   */
  class SimpleConflictMarker
      implements DependencyGraphTransformer
  {
  
      public DependencyNode transformGraph( DependencyNode node, DependencyGraphTransformationContext context )
          throws RepositoryException
      {
          requireNonNull( node, "node cannot be null" );
          requireNonNull( context, "context cannot be null" );
          @SuppressWarnings( "unchecked" )
          Map<DependencyNode, Object> conflictIds =
              (Map<DependencyNode, Object>) context.get( TransformationContextKeys.CONFLICT_IDS );
          if ( conflictIds == null )
          {
              conflictIds = new IdentityHashMap<>();
              context.put( TransformationContextKeys.CONFLICT_IDS, conflictIds );
          }
  
          mark( node, conflictIds );
  
          return node;
      }
  
      private void mark( DependencyNode node, Map<DependencyNode, Object> conflictIds )
      {
          Dependency dependency = node.getDependency();
          if ( dependency != null )
          {
              Artifact artifact = dependency.getArtifact();
  
              String key =
                  String.format( "%s:%s:%s:%s", artifact.getGroupId(), artifact.getArtifactId(),
                                 artifact.getClassifier(), artifact.getExtension() );
  
              if ( conflictIds.put( node, key ) != null )
              {
                  return;
              }
          }
  
          for ( DependencyNode child : node.getChildren() )
          {
              mark( child, conflictIds );
          }
      }
  
  }